Linear fluorescent high-bay

ABSTRACT

A method for implementing lighting utilizes a lighting fixture having a plurality of lateral reflector positions, including selectively installing a first type reflector panel or a second type reflector panel in individual ones of the plurality of lateral reflector positions, the first type reflector panel having a greater uplighting capacity compared to the second type reflector panel, whereby the selectively installing determines, for the lighting fixture, a proportion of uplight versus downlight. For a plurality of tube positions disposed in a plane, a method may include vertically positioning a reflector assembly with respect to the plane. Individual reflector panels may be replaced by flexing the panel. A method may include providing a sensor switch operative to detect an occupant and connect an electrical path when the occupant is detected, and providing a selector for selecting ones of the ballasts to be connected to the electrical path by the sensor switch.

RELATED APPLICATIONS

The present application is a continuation of patent application Ser. No.10/679,228, filed Oct. 2, 2003.

BACKGROUND

1. Field of the Invention

The present invention relates to lighting systems and, moreparticularly, to reflector type fixtures optimized for use in anindustrial or commercial facility.

2. Background of the Invention

Fluorescent lighting fixtures are used in various applications such asbeing recessed in hung ceilings or being used as stand-alone units hung,for example, from the rafters of an industrial or commercial building.Traditionally, fluorescent lighting fixtures have been used in suchrecessed applications because they generate much less heat than othertypes of lighting units, e.g., high intensity discharge, and becausethey may have a physical package with a short height and/or a smallwidth (depending on the number of tubes in the fixture).

Many areas in stores, warehouses, and commercial buildings areilluminated by various free-standing types of lighting fixtures that maybe suspended from the ceiling, such lighting fixtures typicallycontaining lamps such as mercury vapor, metal halide, or sodium types.Industrial or commercial lighting may be classified as being high bay orlow bay, depending on a nominal height of the fixture above the floor ofthe room being illuminated. In most lighting applications it isdesirable to direct the light downward, for example, to illuminateaisles in a store or warehouse, as necessary in a building having a highbay. As a low-power, low-cost alternative to expensive high intensitydischarge (HID) type lamps that may generate excessive heat, requireexpensive and heavy ballasts, or that may be of a design not readilyadaptable to different lighting applications, many commercial lightinginstallations utilize fluorescent lamp fixtures. Such fluorescentfixtures may have a lower wattage requirement and cost. Other reasonsmay dictate choosing fluorescent fixtures, for example, lowertemperatures, smaller and lighter ballasts, power distributionrequirements, lower intensity, etc. Although it may be advantageous toprovide fluorescent lighting in these applications, it may be difficultto provide the necessary efficiency and directivity. A higher efficiencyis desirable, for example, to reduce the number of luminaries to producethe necessary level of illumination. In addition, traditional luminariesmay be inadequate, for example, in buildings such as warehouses, whichhave high ceilings necessary to accommodate high stacking and shelvingof items.

Fluorescent lighting systems may be implemented as so-called “compact”fluorescent devices, as well as conventional “linear” fluorescentfixtures. The newer compact devices typically utilize smaller diameter,shorter fluorescent tubes that may be formed in a “U”. For lightingfixtures of both the compact and linear fluorescent type it may bedifficult to adapt to various lighting requirements and applications ina high bay. Traditional high bay lighting may not be optimized because,although it is important that light be efficiently directed downwardlyfrom a high location onto an illuminated surface, many high bay lightingsituations may include areas that require less light some or all of thetime.

OBJECTS OF THE INVENTION

It is an object of the invention to provide an improved linear typefluorescent lighting fixture that overcomes some of the problems andshortcomings of the prior art, including those referred to above.

Another object of the invention is to provide apparatus and method forselectively configuring a fluorescent lighting fixture for customizing aproportion of uplight versus downlight emitted by the fixture.

Another object of the invention is to provide a modular linearfluorescent lighting fixture and method where individual reflectorpanels of the fixture may be replaced without removing the lightingfixture from its installed location and without disassembling thelighting fixture.

Still another object of the invention is to provide a fluorescentlighting fixture that is configurable between a narrow lightingdistribution pattern and a wider light distribution pattern.

Yet another object of the invention is to provide apparatus and methodfor externally configuring a step dimming of a multiple-lamp fluorescentlighting fixture.

Another object of the invention is to provide a fluorescent lightingfixture having a low profile.

A further object of the invention is to provide a system for fluorescentlighting and method for implementing various lighting control in amaster/slave configuration.

How these and other objects are accomplished will become apparent fromthe following descriptions and the drawings.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a method is providedfor implementing lighting by utilizing a lighting fixture having aplurality of lateral reflector positions, the method includingselectively installing a first type reflector panel or a second typereflector panel in individual ones of the plurality of lateral reflectorpositions, the first type reflector panel having a greater uplightingcapacity compared to the second type reflector panel, whereby theselectively installing determines, for the lighting fixture, aproportion of uplight versus downlight.

In another aspect of the invention, a method for implementing lightingincludes providing a lighting fixture having a plurality of lateralreflector positions, and providing a plurality of reflector panels of afirst type and a second type, the reflector panels for being selectivelyinstalled in respective ones of the plurality of lateral reflectorpositions, where the first type reflector panel has a greater uplightingcapacity compared to the second type reflector panel, and whereselective installation of the reflector panels determines a proportionof uplight versus downlight.

According to another aspect of the invention, a method for achieving adesired proportion of uplight versus downlight includes providing aprogram product operative for selecting between a first type reflectorpanel and a second type reflector panel for installation at a given oneof a plurality of reflector positions, where the first type reflectorpanel has a greater uplighting capacity compared to the second typereflector panel.

In another aspect of the invention, an illuminating system includes afluorescent lighting fixture having a plurality of reflector positions,and a plurality of reflector panels of a first type or a second type,where the first type reflector panel has a greater uplighting capacitycompared to the second type reflector panel, and each of the pluralityof reflector positions is adapted to install one of the first typereflector panel and the second type reflector panel therein.

In another aspect of the invention, a method for implementing lightingincludes providing a fluorescent lighting fixture having a plurality oftube positions disposed in a plane, and providing a reflector assemblyvertically positionable with respect to the plane.

In another aspect of the invention, a method for implementing lightingincludes providing a fluorescent lighting fixture having a plurality oftube positions disposed in a plane, and vertically positioning areflector assembly with respect to the plane, at a selected one of aplurality of vertical reflector positions.

In another aspect of the present invention, a linear fluorescentlighting fixture includes a plurality of tube positions disposed in aplane, and a vertically-positionable reflector assembly, the reflectorassembly having a plurality of reflectors corresponding to the pluralityof tube positions and structured to be vertically positionable withrespect to the plane.

In another aspect of the invention, a method for implementing lightingwith a linear fluorescent lighting fixture having a plurality ofballasts includes providing a sensor switch operative to detect anoccupant within a view and to connect an electrical path when theoccupant is detected, and providing a selector for selecting ones of theballasts to be connected to the electrical path by the sensor switch.

In another aspect of the invention, a linear fluorescent lighting systemincludes a plurality of ballasts, a sensor switch operative to detect anoccupant within a view and to connect an electrical path when theoccupant is detected, and a selector for selecting ones of the ballaststo be connected to the electrical path by the sensor switch.

In another aspect of the invention, a linear fluorescent lightingfixture includes a plurality of fluorescent tube locations, a pluralityof pairs of tube sockets, one pair of sockets being disposed at each ofthe plurality of fluorescent tube locations, a pair of socket mountingplates for holding the plurality of tube sockets, a plurality oflaterally-flexible reflector panels, one of the reflector panels beingdisposed at each of the plurality of fluorescent tube locations, and apair of endcaps each having a plurality of horizontal slots forreceiving edges of ones of the reflector panels, where at least one ofthe reflector panels is removable and insertable with respect to ones ofthe horizontal slots by laterally flexing the reflector panel.

“Downlighting” and “uplighting” are well-known terms used in thelighting industry to refer to fixtures that respectively cast theirlight downwards or upwards. For example, conventional uplighting may beutilized for creating indirect lighting by bouncing light off theceiling and back down, though this is less efficient than directlighting. As used herein, “downlight” and “uplight,” and variations ofthese words, are defined as pertaining to light being emitted from alighting fixture. As used herein, a “panel having an uplightingcapacity” is defined as a panel passing a portion or percentage of lightincident thereupon. For example, a solid metal panel may pass no light,whereas a translucent panel may pass some amount of light therethrough;when such panels are installed above a light source, they have differentrespective uplighting capacities because such metal panel provides nouplighting and such translucent panel provides some amount ofuplighting.

In various aspects of the invention, a chart is used by a lightinginstaller for customizing the proportion of uplighting versusdownlighting in a group of reflector panel positions, where suchpositions are in one or more separate lighting fixtures. A “chart,” asthat term is used herein, is defined as being any table, in any form,adapted for assisting a selection. For example, a chart may use a firstsymbol that represents a solid metal reflector-type panel and a secondsymbol that represents a light-passing reflector-type panel, such as anacrylic reflector panel. The mixing of different types of reflector-typepanels according to their respective uplighting capacity or proportionmay be simplified by use of the chart which specifies a number and/orlocation of first and second reflector-type panels (e.g., metal andacrylic, respectively), and locations where each type is to be placed.Such a chart may be provided, for example, as a template used by anassembly line worker or robot assembling the fixtures, as a labelaffixed to a surface of the lighting fixture, as a routine in a lightingdesign software program, and in various forms in a lighting fixturemanufacturer's product catalog. The chart may present a relationaldatabase where a lighting designer inputs a desired proportion ofuplight versus downlight for an area of a facility, inputs differentdesired proportions for different areas in a room, or inputs differentdesired proportions for different categories of space within a facility.Such a relational database may automatically compute an optimumplacement of individual reflector-type panels, within individualfixtures or groups of fixtures, in order to achieve the desireduplight/downlight proportion(s).

As used herein, a “reflector position” is defined as a lighting fixtureportion adapted for receiving a “reflector panel,” defined as being anyof reflective, translucent, and transparent.

As a result of implementing some of the various aspects of theinvention, different areas in stores, warehouses, and commercialbuildings may be illuminated by use of lighting fixtures that may beeasily adapted for changing a proportion of uplighting versusdownlighting, replacing reflector-type panels, altering a directivity oflighting, providing selectable step dimming, utilizing motion or similardetection switching, and others. A switching of individual ballastsprovides an energy savings and a lower temperature of operation. A highefficiency is provided by utilizing optimized reflector designs. A lowprofile design allows use where available vertical height is limited.

Additional advantages and a more complete understanding of the presentinvention may be derived by referring to the detailed description ofpreferred embodiments and claims when considered in connection with thefigures, wherein like reference numbers refer to similar itemsthroughout the figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a view showing an upper portion of a lighting fixtureaccording to an exemplary embodiment of the present invention.

FIG. 2 is a view showing a bottom portion of the lighting fixture ofFIG. 1

FIG. 3 is a bottom view of a six-tube fixture showing a location ofvarious components including those of a ballast channel assembly,according to an exemplary embodiment of the present invention.

FIG. 4 is a inner view of an endcap for a lighting fixture according toan exemplary embodiment of the present invention.

FIG. 5 is an outer view of the endcap of FIG. 4.

FIG. 6 is a detailed view of a reflector mounting portion of the endcapof FIG. 4.

FIG. 7 is an end view of a cell of a lighting fixture that contains afaceted first type reflector, according to an exemplary embodiment ofthe present invention.

FIG. 8 is an end view of a cell of a lighting fixture that contains afaceted prismatic second type reflector, according to an exemplaryembodiment of the present invention.

FIGS. 9A and 9B are reflector positioning charts used to configurelighting fixtures to provide a desired proportion of uplighting versusdownlighting, according to an exemplary embodiment of the presentinvention.

FIG. 10 is a view of a ballast connected to a socket mounting plate fora lighting fixture in a narrow light distribution configurationaccording to an exemplary embodiment of the present invention.

FIG. 11 is a view of a spacer used for configuring a lighting fixture ina medium light distribution mode according to an exemplary embodiment ofthe present invention.

FIG. 12 is a view of a ballast connected to a socket mounting plate fora lighting fixture in a medium light distribution configurationaccording to an exemplary embodiment of the present invention.

FIG. 13 is a view of a ballast channel assembly showing the respectivelocations of a ballast, a rocker switch, and an infrared detectorassembly according to an exemplary embodiment of the present invention.

FIG. 14 is a view of a rocker switch used in the configuration of FIG.13.

FIG. 15 is a view of an infrared detector assembly used in theconfiguration of FIG. 13.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1-2 show a linear fluorescent high-bay fixture 1 according to anembodiment of the present invention. Individual cells 10 are formed toeach include a linear fluorescent tube 12 and a pair of tube sockets 11.The fluorescent tube 12 is typically a tubular discharge vessel made ofglass, into the end caps of which thermionic cathodes are melted. Thetube 12 is typically formed by being evacuated and filled with argon andmercury. At both end caps of the tube 12, the thermionic cathodes arerouted to the outside as two terminals each. Therefore, the tube 12generally has two electrical terminals (not shown) at each lengthwiseend, and the pairs of sockets 11 are each located so that acorresponding tube 12 may be inserted into a respective pair of sockets11 by moving the tube 12 into position where the terminals slide into alateral slot (not shown), whereupon the tube 12 is rotated until theterminals are engaged with the socket 11 in a known manner. The tube 12typically has a standard length in increments of one foot (e.g., fourfeet) and has a standard diameter in increments of one-eighth inch(e.g., T5=⅝ inch diameter; T8=one inch diameter). Tubes may have avariety of properties such as, for example, those pertaining to theirability to withstand being turned on and off, their light output, theirefficiency, etc. A suitable 54 watt T5 type tube is the model 90209available from General Electric Co. A suitable socket is a model109541.01 available from Vassloh. Each cell 10 has at least onereflector panel 40 located so that a respective tube 12 is positioned ina concave portion with respect to the reflector panel 40. In a fixture1, 100, a gap may be provided (e.g., ˜¼ inch) between bottom-mostportions of adjacent ones of the reflector panels 40, 140, and/orbetween bottom-most portions of adjacent ones of the reflector panels40, 140 and the ballast channel assembly 50. By comparison, conventionalmulti-lamp fluorescent fixtures typically utilize a structure whereadjacent reflector panels touch. Although such a conventional structuremay provide a narrower lighting fixture, this does not consider otherparameters that are important to proper operation of a lighting fixture.The present inventors have determined that by providing theabove-described gaps, a convection type cooling of the fixture may beprovided. It is important that components of a lighting fixture such asthe tubes 12 maintain a desired ambient temperature for long life andproper operation. For example, an optimum ambient temperature for afluorescent lamp may be about 25 degrees C., where a lower or higherambient temperature causes a less than optimum performance of the lamp.In addition, such gaps allow dust and other foreign materials to passthrough the fixture rather than attaching and causing a reduced coolingof the fixture or unhealthy environment. Further, as discussed furtherbelow, the gaps may be used for reaching a lateral side of a reflectorpanel 40, 140 for laterally urging the reflector panel 40, 140 in orderto disengage the flange portions 41, 141 of the reflector panel 40, 140from the corresponding slot portions of the endcaps 30, for removing andreplacing reflector panels 40, 140 without a need to disassemble thefixture 1, 100.

The tube sockets 11 at each end of the light assembly 1 are mounted on arespective socket mounting plate 80 that extends in a widthwisedirection. The socket mounting plates 80 are attached to respectivelengthwise ends of a ballast channel assembly 50 that has a lengthwisedimension located along the center longitudinal axis of the lightingfixture 1. The ballast channel assembly 50 receives electricalconductors such as wires (not shown) from the sockets 11 for connectionto wires or terminals of one or more ballasts 55 mounted to an interiorwall of the ballast channel assembly 50. The ballast 55 receives an ACline voltage. For example, in the U.S., ballast line voltage optionsinclude 120, 208, 240, 277 or 480 volts, whereas in Canada, ballastoptions include 120, 277 and 347 volts. The ballast 55 preferably has acircuit arrangement for the operation of a number (e.g., two) offluorescent tubes, the circuit including an alternating current supply,with a reactance coil and a glow discharge igniter, simply referred toas starter, being required for striking the gas discharge. The reactancecoil and the starter may be replaced by using an electronic ballast(elektronisches Vorschaltgerat) (“EVG”) for an energy-saving operationthat has a high efficiency. Many different types of ballast may besubstituted depending on, for example, weight, heating, costconsiderations, type of tubes, etc. Electrical connections from theballast 55 to the individual sockets XX may be accomplished by usingwell-known wire nuts (not shown) or similar connection devices, or bywires that run directly from individual sockets 11 to push-typeterminals located in a terminal strip portion of the ballast 55.Suitable wire nuts, for example, are a model 773-104 available fromWago, and a suitable ballast for powering a pair of T5 tubes is a modelICN-2S54-90C available from Advance. The wires from the ballast 55 mayalternatively be provided as a harness type assembly having a connectorthat plugs into a corresponding connector on the ballast 55 itself. Sucha harness may also be used when connecting to a ballast having wiresinstead of terminals, so that the ballast may be replaced without a needto rewire the lighting fixture 1.

The lighting fixture 1 includes a hanger assembly 60 for suspending thelighting fixture 1 from a ceiling, rafters, etc. The hanger assembly 60may include metal “V” shaped rods that fit into holes or recesses formedin the ballast channel assembly 50 or in the endcaps 30. A wire or chainmay then be passed through or attached to the V-shaped rod.Alternatively, a rigid metal member may be securely attached to theballast channel assembly in order to provide electrical grounding and/ora more secure structure. The endcaps 30 may be provided with innerpanels 35 that may be used to cover any exposed portion of the top orupper side portion of the fixture 1. An additional top cover plate (notshown) may be provided to cover the top of the lighting fixture 1 inorder to provide a nicer appearance.

FIG. 3 shows a positioning of three individual two-lamp ballasts 55 inthe ballast channel assembly 50, for an exemplary embodiment of alighting fixture 100 having six tubes 11. As can be seen, the narrowprofile of the ballasts 55 allows for placing the ballasts 55 adjacentone another while maintaining a ballast channel 50 having a small width.It is noted that the ballast channel 50 being provided in a same planeas the cells 10 allows either lighting fixture 1 or 100 to have a shortvertical height compared with conventional fixtures that position aballast atop a tube position.

The ballast channel 50 and socket mounting plates 80 are preferablyformed of suitable metal(s) or similar lightweight conductive materials.An endcap 30 is located at each end of the lighting fixture and isconnected to the ballast channel assembly 50 and/or to the correspondingsocket mounting plate 80. Referring to FIGS. 4-8, the end caps 30 may beformed of a plastic, lightweight metal, or similar material, and havingslots 32, 33 formed in ribs 36 located on an inner surface 31 of theendcap 30, the slots 32, 33 for receiving flanged end portions 41 ofreflector panels 40. The end cap 30 is preferably removably attached tothe ballast channel assembly 50 and/or the socket mounting plate 80 sothat the endcaps 30 and reflector panels 40 may be removed for cleaning,replacement, or interchanging. As shown in FIG. 5, the endcap 30 has anouter portion 37 that prevents any of the inner parts of the fixture 1from being exposed. The outer portion 37 has a lateral endmost portionthat may be curved or faceted in order to provide an attractiveappearance.

The reflector panel 40 may be formed having a flexible structure thatmaintains a preformed shape. The flanged end portions 41 are placed incorresponding notches 32, 33 formed in the end caps 30 so that thereflector panels 40 ‘float’ without a need for attachment members tohold the reflector panel 40 to the lighting fixture 1. Where required, agrounding strap or similar structure for grounding a metal reflectorpanel 40 may be provided. Preferably, the grounding strap may be easilyconnected or disconnected to a convenient grounding location such as,for example, to a lug or terminal located at a convenient position alonga metal surface of the fixture 1. It is further preferred that thegrounding strap and terminal location be accessible yet hidden from viewwhen the fixture is installed for operation. The aforementionedpreformed shape may include facets and/or prism-shaped sections,discussed below, that help maintain the shape while also being formed todirect the light in a predetermined manner.

As shown in FIG. 6, the ribs 36 include at each reflector panelattachment location a narrow horizontal slot 33 and a wider horizontalslot 32, where a projection member 34 constitutes a lateral end stop forthe wider horizontal slot 32 and constitutes an upper surface for thenarrow horizontal slot 33. The horizontal slots 32, 33 provide forinterchangeability of reflector panels 40, 140 into the same endcap 30.

As shown in FIG. 7, the reflector panel 40 may be formed as amulti-faceted structure of a thin gauge (e.g., 0.020 inch) metal such asaluminum or similar metal, where the thin flanged end portions 41 of thereflector panel 40 fit into the narrow horizontal slots 33 of theendcaps 30. As shown in FIG. 4, a lengthwise end space 45 is formedbetween an inner wall 38 of the endcap 30 and a reflector panel stoplocation 39 where the lengthwise ends of the reflector panels 40 arelocated when the reflector panels 40 are installed in the endcap 30.This space 45 allows a user to reach inside the lighting fixture andpush the reflector panel 40 at outer sides thereof as shown by thearrows marked as “A” in FIG. 7. By such pushing of the side(s) of thereflector panel 40, the flanged end portions 41 of the reflector panel40 are disengaged from the slots 33 in a direction “B,” allowing theuser to remove the reflector panel 40 from the lighting fixture 1. In asame manner, as shown in FIG. 8, the reflector panel 140 formed of athicker acrylic material may be removed from ribs 36 of the endcaps 30by pushing the reflector panel 140 in a direction “A” which causes theflanged end portions 141 of the reflector panel 140 to become disengagedfrom the slots 33 in a direction “B.” It can be seen that the metalreflector panel 40 has thinner longer flanges 41 compared to thosecorresponding flanges 141 of reflector panel 140. Parameters such as aretention length of the flanges 41, 141 and a stiffness of the reflectorpanel 40, 140 may be varied depending upon a particular fixture design.

The reflector panels 40, 140 may be formed of various materialsdepending on whether it is necessary that they be conductive, opaque,translucent, transparent, of a given weight or structural strength,within a cost budget, fire retardant, attractive, reflective ornon-reflective, smooth or coarse, or with any combination of propertiesor features. In a preferred embodiment, various types of reflectorpanels are provided to be interchangeable at a given reflector panellocation in the lighting fixture 1, or within a group of the fixtures 1.For example, in a high bay facility it may be desirable to changelocations of aisles, heights of shelves, locations of equipment,cubicles, assembly lines, etc. It may also be desirable to lease thefacility to new tenants who have a different use for the area having thelighting fixtures 1. Therefore, the present inventor has determined thatthe lighting fixture 1 or groups of same may be adaptable for modifyinga lighting being provided.

According to a preferred embodiment, it is desired to utilize lineartype fluorescent lighting fixtures for providing uplighting as well asdownlighting. In such a case, an individual lighting fixture 1 may becustomized for providing a desired proportion of uplight versusdownlight, by selecting a reflector panel type for individual cells 10of the lighting fixture 1. For example, when it is desired that aparticular cell 10 have nearly 100% of the usable light for the cell 10be used as downlight, solid metal type reflector panel(s) 40 may beinstalled for that cell. The metal reflector panel 40 is preferablyfinished to have a mirror-like reflectance property. It is noted that aportion of the light emitted from the tube 12 may be absorbed by thereflector panel 40, so that a remaining portion of the light isconsidered as being usable. When it is desired that a proportion of theusable light for a cell 10 be emitted as uplight, reflector panel(s) 140may be installed that have a known translucence, so that the proportionof uplight is thereby controlled. In this manner, by selectivelyinstalling individual reflector panels 40 or 140 at each of the cells10, the uplighting proportion of the fixture 1 having multiple cells 10can be customized. Further, the customizing can be applied to multiplefixtures 1, and to fixtures 1 that can be grouped according to variouscriteria such as, for example, relative placement with respect to areflective surface such as a white wall, relative placement with respectto adjacent fixtures, various photometric or testing information,dimming applications, Visual Comfort Probability (VCP) parameters,dullness or brightness of reflector panels, interior design andaesthetics, etc.

The present inventors has determined that a mixture of different typesof reflector panel may be used in a single fixture or in a group ofindividual fixtures. Providing such a mixture allows the manufacturer,user, or installer to customize the proportion of uplight versusdownlight. For example, a reflector panel made of a solid aluminummaterial reflects nearly all of the incident light and does not allowany light from the fluorescent tube to ‘seep’ through and becomeuplight. A reflector panel may alternatively be formed of an acrylicmaterial so that a percentage of the incident light seeps through thereflector panel and becomes uplight. By consistently forming such anacrylic reflector panel, the percentage of uplight for the reflectorpanel is known and is controlled when manufacturing the reflector panel.An illustrative example is now provided with reference to FIGS. 9A and9B.

In FIG. 9A, a chart is shown for customizing the proportion ofuplighting in a four tube T5 type lighting fixture. In FIG. 9B, a chartis shown for customizing the proportion of uplighting in a six tube T8type lighting fixture. The symbols in the charts represent either a TypeI reflector panel or a Type II reflector panel. In this example, thedark Type I symbols represent solid metal reflector panels such asreflector panels 40 discussed above. The white symbols represent Type IIreflector panels such as acrylic reflector panels 140. The mixing ofdifferent types of reflector panels according to their uplightingproportion may be simplified by use of the chart which specifies anumber of Type I reflector panels, a number of Type II reflector panels,and locations where each type is to be placed. Such a chart may beprovided, for example, as a template used by an assembly line worker orrobot assembling the fixtures, as a label affixed to a surface of thelighting fixture, as a routine in a lighting design software program,and in various forms in a lighting fixture manufacturer's productcatalog. The chart may present a relational database where a lightingdesigner inputs a desired proportion of uplight versus downlight for anarea of a facility, inputs different desired proportions for differentareas in a room, or inputs different desired proportions for differentcategories of space within a facility. Such a relational database mayautomatically compute an optimum placement of individual Type I or TypeII reflector panels, within individual fixtures or groups of fixtures,in order to achieve the desired uplight/downlight proportion(s). In theFIGS. 9A-B charts, it is seen that different uplighting proportions areobtained by selectively placing different type reflector panels atparticular cells 10 within a fixture 1, 100. Corresponding opticconditions are obtained for the particular reflector panel arrangementand are classified according to optic type. Such charts may be providedas labels affixed to a part of the lighting fixture 1, 100 not seen whenthe fixture 1, 100 is installed.

The present example is only illustrative, as any number of differenttypes of materials and shapes of reflector panels may be substituted forone another and a corresponding chart may utilize degrees of freedomappropriate for the respective variables. In other words, individuallighting fixtures may be customized in consideration of the componentparts used to build the fixture, the lighting requirements for givenareas, the number and proximity of other lighting fixtures, time delaysand other implementations being used in conjunction with motion sensors,lighting switch patterns, etc. In a preferred embodiment, reflectorpanels 40, 140 have the same general shape, where reflector panel 40 isformed of a highly polished aluminum and reflector panel 140 is formedof an acrylic so that reflector panel 140 has a light transfer functionwhere a known amount of light passes through reflector panel 140 andbecomes uplight, for a known incident light level and known dimensionalrelation of the light source to the reflector panel 140 surface(s). Moreparticularly, the acrylic reflector panel 140 as shown in FIG. 8 has aflat inner surface formed with a same facet pattern as is shown for thereflector panel 40 of FIG. 7. This inner surface provides a firstsurface reflection of incident light in a manner essentially the same asthe first surface reflection obtained from a metal reflector panel 40.For reflector panel 140, some of the incident light passes to the outerprism-shaped surface where it encounters a second surface reflection sothat a Total Internal Reflection (TIR) of the incident light allows fordirectivity and efficiency of the resultant reflected light. The firstsurface reflection and the second surface reflection combine to createthe downlight from the cell 10 in a highly efficient manner. A portionof the incident light passes (seeps) through the prismatic acrylicreflector panel 140, primarily at the ‘corners’ of the prisms whereadjacent sides meet. Since it is difficult to form the prismatic surfacewith clean and sharp angles at these corners, a curved portion at thecorner causes the incident light to pass through rather than bereflected. Such light becomes scattering and uplight for the cell 10.The light passing through the acrylic reflector panel 140 gets refractedso that a direction of the light rays is slightly altered. The anglesbetween faces of the prism surface may be altered depending on factorssuch as the position of a light source creating angles of incidence, orfor increasing a spread of light from reflector panel 140.

Referring again to FIGS. 9A and 9B, it can be seen that the Type Ireflector panels 40 produce essentially only downlight, inner Type IIreflector panels 140 produce uplight and downlight, and outer Type IIreflector panels 140 produce uplight, downlight, and sidelight. Thesidelight may be further directed by additional reflector panels (notshown) or may be utilized by removing portions of the endcap 30 or theinner endcap panel 35 shown in FIG. 1. The selective installation ofeither panel 40 or panel 140 in a cell therefore effects a controllingthe proportion of uplight versus downlight. Although this process hasbeen described for a single reflector panel per cell 10, the sameprocess may be employed for a lighting fixture having multiple reflectorpanels in a single cell 10. In addition, the selection of reflectorpanels may be influenced by an implementation of a switching scheme forindividual cells 10 of a fixture and/or for groups of cells 10 and/orgroups of fixtures 1, 100. Although the present examples are describedfor a particular type reflector panel 140 made of a clear transparent ortranslucent acrylic, various other compositions and forms may be usedfor providing reflector panels having known seepage of light intouplight. For example, a reflector panel may be formed by vacuummetallizing.

Referring now to FIGS. 10-12, a preferred embodiment provides a spacer65 for selectively adjusting a vertical height of the socket mountingplates 80 with respect to the ballast channel assembly 50. The spacer65, for example, has a projecting portion or tab 66 that fits in arecess or slot formed in the upper surface of the ballast channelassembly 50. In addition, holes 67 are provided in the spacer 65 forattaching the spacer 65 to the ballast channel assembly 50 using screws,bolts, nuts, washers, or other fasteners. Further, holes 68 are providedin the top surface of the spacer 65 for attaching the spacer 65 to thesocket mounting plate 80 as shown in FIG. 12. The illustration of FIG.10 is provided to show the ballast channel assembly 50 being attached tothe socket mounting plate 80 without using a spacer 65. Since the endcap30 having reflector panels 40, 140 in a preferred embodiment is attachedto the ballast channel assembly 50 using the two holes 51 provided ineach end-facing wall of the ballast channel assembly 50, the use of aspacer 65 as shown in FIG. 12 positions the endcap 30 and reflectorpanels 40, 140 in a higher location with respect to the socket mountingplate 80 and corresponding tubes 12. Therefore, when a spacer 65 is usedat each end of the ballast channel assembly 50, the plane coincidentwith the tubes 12 is at a higher location within the endcaps 30 andreflector panels 40, 140, so that the resultant downlight lightdistribution pattern from the fixture 1, 100 is narrowed. Similarly,when removing the spacers 65 from the ballast channel assembly 50, theendcap 30 and reflector panels 40 become disposed at a lower locationwith respect to the socket mounting plate 80 and corresponding tubes 12.Therefore, when a spacer 65 is removed from each end of the ballastchannel assembly 50, the plane coincident with the tubes 12 is at alower location within the endcaps 30 and reflector panels 40, so thatthe resultant downlight light distribution pattern from the fixture 1,100 is widened into a medium distribution pattern. The distributionpatterns of the downlight in this respect are simply narrowed or widenedby the vertical relation of a tube 12 with respect to the bottom openingof each cell 10, which in turn is defined by the particular type of lamp12, the width of the opening at the bottom of an installed reflectorpanel 40, 140, the translucence of the reflector panel 140, the positionof the endcaps, etc. Spacing criteria along and across individualreflector panels or groups of reflector panels, a type of reflectorpanel, a distance between reflector panels 40, 140 and endcaps 30,directivity, brightness, efficiency, reflector panel profile, and othercriteria may be taken into consideration when determining whether aparticular lighting location should have a cell 10 configured in anarrow, medium, or other light distribution pattern.

Other structures may alternatively be employed for vertically offsettingthe plane of the tubes 12 from the reflector panels 40, 140. Forexample, in a typical installation, a position of the reflector panels40, 140 is set by the position of the endcaps 30 since the reflectorpanels 40, 140 may be installed, for example, by inserting the flanges41, 141 of a reflector panel into slots 32, 33 of the endcaps 30. Thepositions of the endcaps 30 may be fixed, so that the vertical adjustingmay only consist of changing a relative position of the socket mountingplates 80. In addition, another method and structure for changing thevertical location of the group of tubes 12 in a fixture 1, 100 maysimply involve swapping socket mounting plates 80. In other words,different socket mounting plates 80 may be used that provide differentvertical offsets for the sockets 11 in relation to the endcaps 30 and/orballast channel assembly 50. By using various socket mounting plates 80,a manufacturer is able to offer fixtures having preset lightingdistribution patterns. It is also possible to allow an end user toreconfigure her fixtures in such a manner at the particular facility.

As shown in FIGS. 13-15, in a preferred embodiment, the lighting fixture1 has a motion detector/switch 57 disposed in the ballast channelassembly 50 and positioned so that the motion detector/switch 57 viewsan area below the lighting fixture 1, 100 through a lens 157. A modelCMRB-6 sensor available from SensorSwitch, Inc. is suitable. Thedetector/switch 57 may be provided with internal switching capabilitiesfor turning on or off electrical power being provided to the ballasts55. The detector/switch 57 turns on the power to the ballasts 55 when aperson or other being enters the area of interest beneath thedetector/switch 57. The detector/switch 57 uses Passive Infrared (PIR)in combination with a Fresnel Lens. As an occupant moves within thefield-of-view, the sensor detects a change in motion and temperature.Every time an occupant moves, an internal time delay circuit may bereset. The detector/switch 57 may provide for an adjustable time delay,for example, from 30 seconds to 20 minutes. After a period of time thedetector/switch 57 will automatically time out, turning the electricalpower to the ballasts 55 off. The sensor's lens 157 typically views inseparate 360° cone-shaped patterns, although this viewing window may bealtered by, for example, blocking particular radial portions. Theseparate cones may be used for different applications according to aheight of the fixture 1, 100 above the facility's floor. For example, aparticular cone viewing at 54° angle may only effective up to a 12-15foot mounting height, and is therefore not typically considered in highbay applications. Other cones may be used to view at particular anglesso that the given cone may only be effective, for example, up to 20 feetwhile other cones may continually maintain their effectiveness up to 35feet. In this manner, the detector/switch 57 may be adapted toparticular applications. The detector/switch 57 in a preferredembodiment effectively connects or disconnects electrical power to asecond switch 58 that controls the number of ballasts 55 to be switchedby the action of detector/switch 57. For example, switch 58 may be amultiple position switch that allows a user to externally select whethera motion detection by detector/switch 57 switches all, some, or none ofthe ballasts 55. In other words, the detector/switch 57 connects ordisconnects electrical power to the ballasts indirectly when the switch58 is placed in series between the detector/switch 57 and the ballasts55.

An exemplary embodiment of the switch 58 is shown in FIG. 14. As shown,the switch 58 is a known rocker type switch having a center-off typeconfiguration. By way of example, when the switch 58 is used in alighting fixture 100 having three ballasts 55 for three correspondingpairs of tubes 12, the rocker switch 58 may be placed in a firstposition to selectively allow the detector/switch 57 toconnect/disconnect electrical power to a first one of the three ballasts55 according to whether the detector/switch 57 has detected an occupantin its field of view. The rocker switch 58 may instead be placed in thethird position, whereby the user selectively allows the detector/switch57 to connect/disconnect electrical power to both the first one of thethree ballasts 55 and a second one of the three ballasts 55. When theuser places the rocker switch 58 in the center-off position, theswitching action of the detector/switch 57 is not connected to theballasts. In practice, this center-off position may be used for assuringthat a third one of the three ballasts remains connected to electricalpower to provide a minimum lighting to a given location while allowingthe same fixture 100 to be changed for a step dimming type action by thedetector/switch 57. The ability to configure the step dimming of alighting fixture 1, 100 externally of the fixture is highly advantageousfor the user, who thereby avoids opening the fixture for such areconfiguring. The switch 58 may be chosen in various forms and/orconfigurations for particular lighting applications. For example, theswitch 58 may be remote to the fixture 1, 100, may be a DIP type, arotary type, a paddle type, an other type, may be connected and/orcontrolled by a timer or ambient lighting sensor, may be temperaturecontrolled, may be controlled by wireless device, may be programmed,etc. In addition, a master/slave relationship may be configured for oneor more groups of lighting fixtures 1, 100 so that, for example, one ormore of the switches 58 in a particular group may be used to configure astep dimming for the group. Similarly, for example, one or more of thedetector/switches 57 may be used in a master/slave configuration forcausing electrical power to be connected to various ones of the ballasts55 for a given group of lighting fixtures 1, 100. A lighting system mayinclude a controller (not shown) for remotely controlling one or more ofthe switches 58. For example, a digitally addressable lighting interface(DALI) protocol may be adapted for implementing such a control.

The placement of the ballast channel assembly 50 in a same lateral planewith the cells 10 that contain the reflector panels 40, 140 and thetubes 12, allows the lighting fixture 1, 100 to have a low profile, forexample approximately less than 5 inches high. An optional hookaccessory (not shown) may be provided for use in an alternate method ofhanging the fixture 1, 100. The lighting fixture 1, 100 may beconfigured for hard wiring or provided with an optional cord accessory.The fixture may be formed for adding lens and/or wire-guard accessories.

Other features that may be utilized with the lighting fixtures 1, 100include use of a programmed rapid-start ballast system in order tooptimize lamp life, increased structural integrity for assuring anupgraded 90° C. case temperature rating, use of a ballast assembly forobtaining 0° F. cold starting capability, end of lamp life protectionthat removes lamp power when a lamp is approaching a predeterminedcondition, design changes that allow for use of different nominaloperating temperatures such as by use of different lens systems, varioustypes of lamp sockets, multiple level control of lighting parameters andillumination, different numbers of lamps per fixture, instant-start,high output ballast factors, and others.

While the principles of the invention have been shown and described inconnection with specific embodiments, it is to be understood that suchembodiments are by way of example and are not limiting.

1. A method for implementing lighting by utilizing a lighting fixturehaving a plurality of lateral reflector positions, the method comprisingselectively installing a first type reflector panel or a second typereflector panel in individual ones of the plurality of lateral reflectorpositions, the first type reflector panel having a greater uplightingcapacity compared to the second type reflector panel, whereby theselectively installing determines, for the lighting fixture, aproportion of uplight versus downlight.
 2. The method of claim 1 whereinthe lighting fixture includes at least one socket at each of theplurality of lateral reflector positions, the method further comprisingproviding a switch member adapted to connect or disconnect electricityto selected ones of the plurality of sockets.
 3. The method of claim 1further comprising interchanging a reflector panel of the first type anda reflector panel of the second type at least one of the reflectorpositions.
 4. The method of claim 3, wherein at least one of thereflector panels is removable and insertable by laterally flexing thereflector panel.
 5. The method of claim 1 further comprising referringto a chart for selecting between the first type reflector panel and thesecond type reflector panel for installation at a given one of theplurality of reflector positions.
 6. The method of claim 5 wherein thechart is based on the number of lateral reflector positions and therespective translucences of the first type reflector panel and thesecond type reflector panel.
 7. The method of claim 5 wherein the chartis based on lighting requirements for given areas within a facility. 8.The method of claim 5 wherein the chart is based on a number andproximity of other lighting fixtures.
 9. The method of claim 5 whereinthe chart is based on operational logic of at least one motion sensor.10. The method of claim 5 wherein the chart is based on at least onelighting switch pattern being implemented for the plurality of reflectorpositions.
 11. The method of claim 5 wherein the chart is based on atleast one lighting switch pattern being implemented for a plurality oflighting fixtures.
 12. The method of claim 5 wherein the chart is aprogram product implemented on a computer.
 13. A method for implementinglighting comprising: providing a lighting fixture having a plurality oflateral reflector positions; and providing a plurality of reflectorpanels of a first type and a second type, the reflector panels for beingselectively installed in respective ones of the plurality of lateralreflector positions, wherein the first type reflector panel has agreater uplighting capacity compared to the second type reflector panel,and wherein selective installation of the reflector panels determines aproportion of uplight versus downlight.
 14. The method of claim 13further comprising providing a chart that is referenced for selectingbetween the first type reflector panel and the second type reflectorpanel for installation at a given one of the plurality of reflectorpositions.
 15. The method of claim 14 wherein the chart is based on thenumber of lateral reflector positions and the respective translucencesof the first type reflector panel and the second type reflector panel.16. A method for achieving a desired proportion of uplight versusdownlight, the method comprising providing a program product operativefor selecting between a first type reflector panel and a second typereflector panel for installation at a given one of a plurality ofreflector positions, wherein the first type reflector panel has agreater uplighting capacity compared to the second type reflector panel.17. The method of claim 16 wherein the program product is adaptable toassist the selecting according to a user input that includes at leastone of: identifying component parts in the fixture; identifyingoperational parameters of the fixture; identifying lighting requirementsfor given areas to be lighted; identifying a number, type, illuminationlevel and/or proximity of other lighting fixtures; identifying animplementation being used in conjunction with a motion sensor; andidentifying lighting switch patterns.
 18. The method of claim 17 whereinthe implementation being used in conjunction with a motion sensorincludes a time delay for disconnecting an electrical connection to thefixture.
 19. An illuminating system comprising: a fluorescent lightingfixture having a plurality of reflector positions; and a plurality ofreflector panels of a first type or a second type, wherein the firsttype reflector panel has a greater uplighting capacity compared to thesecond type reflector panel, and each of the plurality of reflectorpositions is adapted to install one of the first type reflector paneland the second type reflector panel therein.
 20. The system of claim 19wherein the first type panel is formed of an acrylic.
 21. The system ofclaim 19 wherein the plurality of panels are prismatic.
 22. The systemof claim 19 wherein the first type panel is formed by vacuummetallizing.
 23. The system of claim 19 wherein the first type panel hasa multi-faceted partial polygon profile.